From patchwork Fri Mar 3 08:55:10 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Reshetova, Elena" X-Patchwork-Id: 9602247 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 8B887602B4 for ; Fri, 3 Mar 2017 09:02:35 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 801F228578 for ; Fri, 3 Mar 2017 09:02:35 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 74AC9285A3; Fri, 3 Mar 2017 09:02:35 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 184F528578 for ; Fri, 3 Mar 2017 09:02:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751675AbdCCJCc (ORCPT ); Fri, 3 Mar 2017 04:02:32 -0500 Received: from mga11.intel.com ([192.55.52.93]:55568 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751137AbdCCJCY (ORCPT ); Fri, 3 Mar 2017 04:02:24 -0500 Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 03 Mar 2017 00:55:35 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.35,236,1484035200"; d="scan'208";a="1137384883" Received: from fkowalsk-mobl.ger.corp.intel.com (HELO elena-ThinkPad-X230.ger.corp.intel.com) ([10.252.33.72]) by fmsmga002.fm.intel.com with ESMTP; 03 Mar 2017 00:55:31 -0800 From: Elena Reshetova To: linux-kernel@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org, linux-btrfs@vger.kernel.org, peterz@infradead.org, gregkh@linuxfoundation.org, jbacik@fb.com, clm@fb.com, dsterba@suse.com, Elena Reshetova , Hans Liljestrand , Kees Cook , David Windsor Subject: [PATCH 01/17] fs, btrfs: convert btrfs_bio.refs from atomic_t to refcount_t Date: Fri, 3 Mar 2017 10:55:10 +0200 Message-Id: <1488531326-21271-2-git-send-email-elena.reshetova@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1488531326-21271-1-git-send-email-elena.reshetova@intel.com> References: <1488531326-21271-1-git-send-email-elena.reshetova@intel.com> Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova Signed-off-by: Hans Liljestrand Signed-off-by: Kees Cook Signed-off-by: David Windsor --- fs/btrfs/volumes.c | 8 ++++---- fs/btrfs/volumes.h | 2 +- 2 files changed, 5 insertions(+), 5 deletions(-) diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index b124462..a8fd2e9 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -5295,22 +5295,22 @@ static struct btrfs_bio *alloc_btrfs_bio(int total_stripes, int real_stripes) GFP_NOFS|__GFP_NOFAIL); atomic_set(&bbio->error, 0); - atomic_set(&bbio->refs, 1); + refcount_set(&bbio->refs, 1); return bbio; } void btrfs_get_bbio(struct btrfs_bio *bbio) { - WARN_ON(!atomic_read(&bbio->refs)); - atomic_inc(&bbio->refs); + WARN_ON(!refcount_read(&bbio->refs)); + refcount_inc(&bbio->refs); } void btrfs_put_bbio(struct btrfs_bio *bbio) { if (!bbio) return; - if (atomic_dec_and_test(&bbio->refs)) + if (refcount_dec_and_test(&bbio->refs)) kfree(bbio); } diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h index 59be812..ac0bf7d 100644 --- a/fs/btrfs/volumes.h +++ b/fs/btrfs/volumes.h @@ -298,7 +298,7 @@ struct btrfs_bio; typedef void (btrfs_bio_end_io_t) (struct btrfs_bio *bio, int err); struct btrfs_bio { - atomic_t refs; + refcount_t refs; atomic_t stripes_pending; struct btrfs_fs_info *fs_info; u64 map_type; /* get from map_lookup->type */